Low-temperature liquid explosive composition

ABSTRACT

A low-temperature liquid explosive suitable for use at -60* F or above comprising nitromethane and methylene chloride in a 7:3 ratio by weight and from about 2-12 percent diethylene triamine based on the weight thereof.

United States Patent [191 Runge et a1.

[ LOW-TEMPERATURE LIQUID EXPLOSIVE COMPOSITION [75] Inventors: Wallace F. Runge, Terre Haute,

Ind.; Donald W. Edwards, Lehighton, Pa.

[73] Assignee: Commerical Solvents Corporation,

Terre Haute, Ind,

[22] Filed: Aug. 25, 1972 [21] Appl. No.: 283,861

[52] US. Cl. 149/89, 149/109 [51] Int. Cl C06b 7/00 [58] Field of Search 149/89, 90, 109, 91

[56] References Cited UNITED STATES PATENTS 3,713,915 1/1973 Fast 149/89 X 11] 3,798,092 [451 Mar. 19; 1974 Primary ExaminerStephen J Lechert, Jr. Attorney, Agent, or FirmRobert H. Dewey; Howard E. Post [5 7 ABSTRACT A low-temperature liquid explosive suitable for use at 60 F or above comprising nitromethane and methylene chloride in a 7:3 ratio by weight and from about 2-12 percent diethylene triamine based on the weight thereof.

4 Claims, No Drawings LOW-TEMPERATURE LIQUID EXPLOSIVE COMPOSITION BACKGROUND OF THE INVENTION This application relates to a low-temperature liquid explosive composition. In a particular aspect, this invention relates to explosive nitromethane compositions which freeze below about 40 F.

Nitromethane is a very stable compound which can be detonated only under very severe conditions of confinement and shock. However, it is known from Canadian Pat. No. 490,744 that nitromethane can be rendered cap-sensitive by the addition of a minor proportion of a sensitizing agent, many of which are known. Amines and diamines are particularly effective for this use.

It is also known from R. S. Egly and Q. R. Jeffries U.S. Pat. No. 3,288,867 that nitromethane can be stabilized against detonation by the addition of a minor proportion of a stabilizing substance, e.g., methylene chloride.

N itromethane is particularly useful for explosive uses in remote areas because it can be transported over rough terrain in ordinary shipping containers without risk of detonation. It can then be easily sensitized by mixing a sensitizer therewith at the site of use and be used promptly. However, nitromethane solidifies at about F so that at temperatures below that, the sensitizer cannot be satisfactorily mixed nor can the nitromethane be delivered easily to the bore holes, etc. Furthermore, most of the common sensitizers, such as ethylene diamine and benzylamine are insufficiently soluble at, e.g., 40 F, to function satisfactorily and the mixture loses its sensitivity as the sensitizer separates at increasingly lower temperatures. Yet most of the common diluents which might act as antifreeze agents also act as stabilizers, thus reducing the utility of the mixture. Accordingly, a method is needed for maintaining nitromethane in the liquid state below its freezing point, but without rendering it more stable to detonation, nor sensitizing it making transportation hazardous.

SUMMARY OF THE INVENTION It is an object of this invention to provide a lowtemperature explosive composition.

It is another object of this invention to provide a nitromethane composition which remains liquid at temperatures below the freezing point of nitromethane, but which can be readily sensitized to detonation by incorporating therein a sensitizer.

Other objects will be apparent to those skilled in the art from the disclosure herein.

It has been discovered that nitromethane mixtures with methylene chloride in a 7:3 by weight ratio and additionally containing 2-12 percent by weight of diethylene triamine sensitizer remain liquid at temperatures below about 40 F, but without loss of sensitivity to detonation. This is particularly surprising because according to U.S. Pat. No. 3,288,867, methylene chloride is a stabilizer for nitromethane in about a 4:6 ratio.

DETAILED DISCUSSION The low-freezing explosive compositions of the present invention include mixtures of nitromethanemethylene chloride compositions in the range of l.8-3:l by weight (i.e., 65-75 percent nitromethane),

by weight, preferably 4-12 percent, based on the 1 weight of the nitromethanemethylene chloride mixture.

The materials used in the practice of this invention are commercially available and the usual grades of commerce are suitable.

The invention will be better understood with reference to the following examples. It is understood, however, that these examples are presented for illustration only and it is not intended that the invention be limited thereby.

EXAMPLE 1 A solution of 70 percent nitromethane and percent methylene chloride was prepared. The freezing point of the mixture was below about F. It was divided into six portions and sensitized with diethylene triamine at concentrations of 2, 4, 6, 8, l0 and 12 percent by wt respectively. These mixtures were tested for sensitivity by placing a portion of each in a one-pint paint can having 2 inch diameter opening. The initiator was 100 grain primacord formed into three concentric 1 rings, the largest of which was just small enough to pass through the can opening. The primacord was then connected to a blasting cap through a suitable switch to a battery.

The compositions were then cooled to 40 F and the primacord was fired. All compositions detonated satisfactorily.

EXAMPLE 2 The experiment of Example 1 was repeated in all essential details except that the compositions were chilled to 60 F. The compositions containing 2, 4, 6, and 8 percent sensitizer failed to detonate, but those containing 10 and 12 percent detonated satisfactorily.

EXAMPLE 3 A mixture of percent nitromethane -30 percent methylene chloride was sensitized by mixing with 2 percent diethylene triamine. The explosive properties were measured; the results obtained were as follows:

Velocity, 1%" diameter 17,427 ft/sec at 40F Friction and impact sensi- Negative tivity at 40 Friction and impact sensi- Negative tivity at ambient temperature Critical diameter at 40] 1% EXAMPLE 4 The experiment of Example 3 was repeated in all essential details except the concentration of sensitizer was 12 percent. The results were as follows:

Velocity. 9" diameter at 40F l9,830 ft/sec Velocity. 9" diameter at ambient 22.796 Friction and impact sensitivity Negative at ambient temperature Critical diameter at ambient A inch temperature 3. The composition of claim 1 wherein the nitromethane and methylene chloride are present in ratio of about 7:3 by weight and the diethylene triamine is pres ent in a proportion of 10 percent based on the weight thereof.

4. A nitromethane composition which can be sensitized to detonation by strong shock with the addition of 2-12 percent diethylene triamine and having a freezing point below about 40 F, consisting of nitromethane and methylene chloride in a weight ratio of about 7:3

respectively.

=0 =k wk 

2. The composition of claim 1 wherein said diethylene triamine is present in a proportion of 4-12 percent based on the weight of nitromethane and methylene chloride.
 3. The composition of claim 1 wherein the nitromethane and methylene chloride are present in ratio of about 7:3 by weighT and the diethylene triamine is present in a proportion of 10 percent based on the weight thereof.
 4. A nitromethane composition which can be sensitized to detonation by strong shock with the addition of 2-12 percent diethylene triamine and having a freezing point below about -40* F, consisting of nitromethane and methylene chloride in a weight ratio of about 7:3 respectively. 